Screw-adjustable wrench (Merrick and Coes)
Llave de tornillo ajustable (Merrick y Coes)
- Date
- 1835-1841 · confidence medium
- Place
- Worcester, Massachusetts, United States
- Credited to
- Solymon Merrick; Loring Coes
- Field
- Tools
⚠️ Disputed: the sources disagree.
What it is
A wrench with one fixed jaw and one jaw moved along a worm screw, adaptable to different nut sizes. Merrick patented an early model in 1835, and Loring Coes of Worcester improved it in 1841 with the curved-handle jaw that became popular.
Authorship is disputed: Edwin Beard Budding patented an adjustable spanner in Britain in 1842, and the legend of Charles Moncky's 'monkey wrench' has no documentary support. The first well-dated screw-adjustable wrench is American.
What it led to
- a single wrench for nuts of different sizes
- bicycle, railway and automobile mechanics
- the modern adjustable wrench of Johansson and Bahco